1. Field of the Invention
The present invention is related to a biological substance analyzing method, for detecting detection target substances within liquid samples with a sensor portion provided in a reaction chamber, and a biological substance analyzing cell, chip, and apparatus.
2. Description of the Related Art
Presently, analysis and quantification of biological substances such as sugars, proteins, and nucleic acids is being performed daily in a wide range of fields, such as clinical examinations, food inspection, and environmental inspections. There are various types of biological substance analysis and quantification methods according to the types of biological substances which are the targets of analysis and quantification. Some of these methods utilize reactions between biological substances and substances that have affinities for the biological substances. For example, quantification methods that utilize antigen antibody reactions are established as highly sensitive and reliable immunoassay methods, and are commonly used in a wide range of fields such as clinical examinations. However, if commercially available reagent kids are employed, each of the multitude of reactions take time, and expedient tests are difficult when there are great amounts of samples. This is because the kinetic energy at a specific temperature controls the reaction speed by the frequency at which molecules collide with each other.
Particularly in antigen antibody reactions in which one of the antigens and the antibodies are immobilized, the molecular collision frequency becomes extremely low, and the reaction speed also decreases correspondingly. Use of ultrasonic waves during reactions in order to increase reaction speeds has been described in U.S. Pat. No. 4,575,485, Japanese Unexamined Patent Publication No. 10(1998)-267927, and European Patent Publication No. 0767376, as a solution to resolve this issue. In this case, it is considered that the ultrasonic waves operate on the antigens or the antibodies which are not immobilized, to increase the collision frequency thereof with respect to the immobilized antibodies or antigens, to promote binding reactions.
U.S. Pat. No. 4,575,485 and Japanese Unexamined Patent Publication No. 10(1998)-267927 disclose inventions in which molecular vibrations are caused by ultrasonic waves to increase collision rates thereof with surrounding substances, thereby increasing reaction speeds. Further, the invention of Japanese Unexamined Patent Publication No. 10(1998)-267927 is characterized by modulating the frequency of the ultrasonic waves to disrupt the state of vibration, to cause translational movement over a wider range. European Patent Publication No. 0767376 discloses an invention that promotes antigen antibody reactions by applying minute voltages for short amounts of time (several tens of seconds or fifteen seconds) without causing electrolysis to occur in immune substances.
However, in the methods disclosed in U.S. Pat. No. 4,575,485 and Japanese Unexamined Patent Publication No. 10(1998)-267927, there is a problem that reaction speed is not improved when the concentration of immune substances is low even if the immune substances are caused to vibrate, because the amount of other immune substances in the vicinities thereof is low. In addition, in such low concentration situations, the amount of immune substance that can be detected at a sensor portion depends on the dispersion speed of the substance. Therefore, it is considered that a great improvement in detection sensitivity cannot be expected. Biological substances (such as blood, urine, and saliva) which are targets of immunodiagnosis commonly contain salt, and the electrical responsiveness of the substances themselves is high. Therefore, promotion of immune reactions using electrical fields may adversely affect these substances, and accordingly the method disclosed in European Patent Publication No. 0767376 is not favorable.